There are some commands that as I get more and more familiar with Rstudio I find myself typing again and again.
Keyboard shortcuts are helpful (disclaimer: these mac versions).
Option-Command-i will open a new Rmarkdown code chunk.
Option - is a handy way of typing assignment (<-)
Shift-Command-M is a fast way of adding a pipe (%>%)
A little googling and here is a whole list that I am yet to learn.